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Title: Can anyone explain the process of how sound enters our ear and goes to the brain Post by: algxosports12 on Jan 8, 2014 Little detail necessary and as simple as possible.
Thanks! Title: Re: Can anyone explain the process of how sound enters our ear and goes to the brain Post by: padre on Jan 8, 2014 Here's a good one
https://biology-forums.com/index.php?topic=3145.0#top (https://biology-forums.com/index.php?topic=3145.0#top) Title: Re: Can anyone explain the process of how sound enters our ear and goes to the brain Post by: bio_man on Jan 8, 2014 Physiology of Hearing
1. Properties of Sound a. Sound is a pressure disturbance produced by a vibrating object and propagated by the molecules of the medium. b. Frequency is the number of waves that pass a given point in a given time. c. Amplitude, or height, of the wave reveals a sound’s intensity (loudness). 2. Airborne sound entering the external acoustic meatus strikes the tympanic membrane and sets it vibrating. 3. The resonance of the basilar membrane processes sound signals mechanically before they ever reach the receptors. 4. Transduction of sound stimuli occurs after the trapped stereocilia of the hair cells are deflected by localized movements of the basilar membrane. 5. Impulses generated in the cochlea pass through the spiral ganglion, along the afferent fibers of the cochlear nerve to the cochlear nuclei of the medulla, to the superior olivary nucleus, to the inferior colliculus, and finally to the auditory cortex. 6. Auditory processing involves perception of pitch, detection of loudness, and localization of sound. Title: Re: Can anyone explain the process of how sound enters our ear and goes to the brain Post by: minacat92 on Jan 8, 2014 Airborne sound waves enter external acoustic meatus; will hit tympanic membrane and vibrate;
vibrations will transmit onto auditory ossicles; as it moves along the 3 bones the signal is amplified; the ossicles will transmit those vibrates to the oval window (stapes sits in the oval window), the oval window transmits the vibration to the vestibule and then on to the cochlea & this creates a wave motion of the cochlear fluid (→refers to endolymph within the cochlea); waves of the endolymph will stimulate mechanoreceptors cells called cochlear hair cells (apical end covered in stereocilla not actually cilia, rather microvilli]; hair cells give their sensory input to fibers of the cochlear nerve; ← fibers coil around the basal end of the hair cells. stimulated hair cells depolarize and initiate a graded potential→ release glutamate onto the afferent cochlear fibers(→the axons of bipolar cells, somas reside in spiral ganglion); bipolar cells project impulses onto the cochlear nuclei of the medulla → info passes to thalamus & axons of thalamic nuclei project to the primary auditory cortex(→ conscious awareness of sound; located in temporal lobe) |